I'm on the road on a short trip (120 miles) in the motorhome; due to traffic, I didn't put the selector into OD until about 1/3 of the way here. It usually shifts into OD at around 50-55 mph. Never did shift, stayed in 3rd.

I had the coach serviced a week ago, and it worked normally. The only messing around I did was to spray lube on the IP shaft, as it wasn't returning to idle like it should. That's normal now.

I checked the TPS, and it's secure.

Temps and performance are otherwise normal.

Any ideas?